1. Field of the Invention
The invention relates to lubricating oils, and particularly to oils suitable for admixing with water to form hydraulic fluids and the like. The invention is more particularly concerned with an aqueous lubricant system containing a metal dithiophosphate and a system of solubilizers for said dithiophosphate.
2. Discussion of the Prior Art
With increasing use of hydraulic fluids and the like, there are more and more sophisticated machine systems which demand closer tolerances to perform new and more difficult functions. They therefore require better thermal and oxidative stability, and, for many hydraulic systems the fluids must have enhanced antiwear properties.
In addition to systems containing fluids made up of oil and water, oil systems per se often accidentally come into contact with water, as by leakage around seals or worn parts or through condensation.
One very effective antiwear agent for compounding with a functional fluid is a metal dihydrocarbyl dithiophosphate. These are illustrated, for example, in U.S. Pat. No. 4,101,429, which discloses a lubricating oil comprising oil and a dithiophosphate mixed with certain dimeric acids and a reaction product of alkenylsuccinic anhydride and polyalkylene polyamines. Also, U.S. Pat. No. 4,094,800 teaches a lubricating oil composition containing oil and a basic dithiophosphate mixed with a nonacidic compound comprising a reaction product of a succinic anhydride and an alcohol and an amine. No art is known that teaches the particularly compositions of this invention, however.